I would like to find out how many lights I need to grow a bougainvillea and p. Afra's well indoors. Specifically I am looking for how many photons an hour these plants require. It would be cool to create a list for common tropical that come inside for winter.
Minimum lighting requirements
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cbroad
Omono
Photons per hour? I have no idea...
In my opinion, more light the better. I feel like to keep up plant vigor, the minimum amount of light needed for most indoor plants would be 20,000 lumens, so that would be a 4' 4 tube high output fluorescent light. Those incandescent spot lights are useless for encouraging plant growth.
If you're talking about LEDs, than I don't really know, I have little experience with decent powered LEDs... I would guess anything less than a 100w fixture is useless for vigor. As far as PAR output for LEDs, I'm still not convinced high PAR actually induces vigor.
In my opinion, more light the better. I feel like to keep up plant vigor, the minimum amount of light needed for most indoor plants would be 20,000 lumens, so that would be a 4' 4 tube high output fluorescent light. Those incandescent spot lights are useless for encouraging plant growth.
If you're talking about LEDs, than I don't really know, I have little experience with decent powered LEDs... I would guess anything less than a 100w fixture is useless for vigor. As far as PAR output for LEDs, I'm still not convinced high PAR actually induces vigor.
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cbroad
Omono
If you really want good growth, look into HID lights like Metal Halide or High Pressure Sodium fixtures.
I used to Mh and HPS bulbs but for my current indoor setup I do not have much space and I am afraid of the heat and fire hazards. So I switched to HIDLED grow lights and so far they work well, I have 2 big ones that pull around 125watts each. The amount of photons per hour is high for each one also. There is all kinds of stuff about weed photon absorption rate but not bougainvilleas that I can find. I want to make sure I have strong enough lights.
And there isn't any data hardly. But I want to find out
0soyoung
Imperial Masterpiece
How many photons is needed, depends on the wavelength of the light, let's say green light. 20,000 lumens is about 10^20 green photons per second; that is 100,000,000,000,000,000,000 green photons per second. Multiply by 360 seconds/hour to get the count of green photons per hour, and that is just for the equivalent of full shade.
Full shade growing light levels are 2,000 to 20,000 lux. 1 lux = 1 lumen per square meter. With a fluorescent tube (idealized to an infinite line) energy density drops linearly with the distance from it. With a spherical or point source the density drops with the square of the distance. With an array large enough to be planar, the energy density tends toward being independent of distance. So, one wants lights arrayed to approximate a planar light source.
Full shade growing light levels are 2,000 to 20,000 lux. 1 lux = 1 lumen per square meter. With a fluorescent tube (idealized to an infinite line) energy density drops linearly with the distance from it. With a spherical or point source the density drops with the square of the distance. With an array large enough to be planar, the energy density tends toward being independent of distance. So, one wants lights arrayed to approximate a planar light source.
It's a huge issue. I have found that brand and design is critical for LED grow lights. They can have all the watts in the world and yet not do shit.
Infact it's so important I am thinking about getting a meter to measure.
Gustavo Martins
Omono
Generally and In terms of PAR:
< 30 µE m−2s−1 shade trees
30 - 60 µE m−2s−1 medium
> 60 µE m−2s−1 high light requirements trees.
< 30 µE m−2s−1 shade trees
30 - 60 µE m−2s−1 medium
> 60 µE m−2s−1 high light requirements trees.
Gustavo Martins
Omono
Correction
Generally and In terms of PAR:
30 µE m−2s−1 minimum
30 - 60 µE m−2s−1 shade tolerant trees
60 - 90 µE m−2s−1 medium light
> 90 µE m−2s−1 high light requirement trees
Generally and In terms of PAR:
30 µE m−2s−1 minimum
30 - 60 µE m−2s−1 shade tolerant trees
60 - 90 µE m−2s−1 medium light
> 90 µE m−2s−1 high light requirement trees
Gustavo Martins
Omono
But plants don’t use much green light do they?
0soyoung
Imperial Masterpiece
Indeed.
But real life photosystems are quite complicated and each adsorbs at two different wavelengths; 630 nm served my purposes for producing a ball park figure for photons per hour.
Gustavo Martins
Omono
Define high PAR and vigor. Otherwise your talking abstract. And yes, too much light can cause photoinibition although I think that’s quite difficult with home set ups
cbroad
Omono
I guess what I meant is a high PPFD.
PAR (photosynthetic active radiation): The spectral range of a light source that photosynthetic organisms are able to use in the process of photosynthesis.
A lot of LEDs claim adequate PAR with a high PPFD, but this not always the case, especially with weaker wattage lights. I've "heard" less than 100w LED lights are equivalent to about 9,000 to 10,000 lumens, which translates to "poor" plant vigor. I don't use LEDs so I don't know, but from other people's experience, the lower wattage ones are too weak and not worth the high cost.
VIGOR: physical strength and good health.
Plant vigor can be hard to explain without a good benchmark for a specific plant's growth. Obviously this a sliding scale; one must understand how much growth a certain plant can produce given an optimum environment. If someone growing plants doesn't understand plant vigor, than this discussion is pointless. A person understands plant vigor when they see a lack of growth or exceptional growth, but without that benchmark they couldn't understand the dual nature of "plant vigor." You'll know plant vigor when you see it...
So I would define "plant" vigor as exceptional growth, fully formed leaves (not stunted or etiolated growth), a healthy foliage and stem color (not discolored or washed out looking), tight internodal spacing, and the ability to withstand the vagaries of the specific environment and continue to produce healthy growth...
So in my attempt to give a short explanation to the original poster, without bombarding them with stats that may or may not help them with their question, I chose to try to make the explanation simple. So yes, I was speaking somewhat abstractly.
TYPICALLY with grow lights, higher wattages usually means higher light output, which usually translates to "good" growth. From the outset, I stated "I" don't have much experience with LEDs, but people I know that have used them have been quite disappointed when they were talked into buying an expensive low wattage LED light, by a store clerk, that wanted to hustle them into dropping big bucks on a sub par grow light, that they promised would replace their HID grow light with increased plant growth, but instead they were left with an expensive light that is annoying to look at and didn't do shit for plant growth. I just didn't want the OP to fall for the same trap...
cmeg1
Imperial Masterpiece
Seems what PAR level at what stage of growth your tree is in is what is important....now just go and buy a $500 par meter lol!
A good LED will have their par measurements for open air growing posted on their website.
That is what I go by to determine the intensity of my led for my pine starts indoors.
HLG posts their measurements online.
Here is a good primer on light intensity.
https://growace.com/blog/why-is-par-rating-a-big-deal-for-indoor-grow-light-systems/
A good LED will have their par measurements for open air growing posted on their website.
That is what I go by to determine the intensity of my led for my pine starts indoors.
HLG posts their measurements online.
Here is a good primer on light intensity.
https://growace.com/blog/why-is-par-rating-a-big-deal-for-indoor-grow-light-systems/
Attachments
Mike Hennigan
Chumono
It’s not the number of photons that matter, it’s the motion of the wave ?
Gustavo Martins
Omono
Yes the last part is also true.
I think you can rent a radiometer or Join a planted tank community. They usually have one.
TN_Jim
Omono
Exactly
but to test anything, a good scientificly valid PAR meter is requisite...same with pH meter, but if I had to choose one, I’d go photons
so how many lights are needed? well one sodium real close if you plan on eating it
the problem with led as I understand is they don’t individually cover the spectrum traditional bulbs do...so if you mix several spectral hues of led radiation you get to beating the old sodium’s, without the light furnace; electric bill; looking directly at the eye of Sauron whenever you go into your garage, office, spare bedroom, where ever -instead bathing in the conglomerate of all of you led lights combined providing you the mothership purple in said room/space.
if you elect to have non-electric-lavender liftoff, go with the led lights that produce a more comfortable typical lightbulb glow...but it is my understanding that these are not going to hit your max PAR wave as close to other led in attempt to replicate the sun
I could naturally be wrong about this. I’m looking for a space bulb myself...
1 bulb, very close
0soyoung
Imperial Masterpiece
An LED has the advantage that it only produces a single wavelength of light - it is a property of the particular semiconductor material of which they are made. So one picks the wavelengths needed and puts those specific chips on a small ceramic circuit board (COB = chip on board). Array a number of these and you've got a COB LED grow light unit. THIS IS THE EURICA DISCOVERY OF THE WEED GROWERS! Having made LEDs in a lab in 1968, I'll claim that solid state physicists have known this for more than half a century now, it just took this long to do the materials science work to make LED chips of any color one might want.
btw, 'white light' LED for home lighting are actually made of 3 LEDs. Tuning the red and blue LED intensities (by the size of the individual semiconductor chips) produces the apparent color temperature.
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